Manufacture of rectifier elements



PatentedNom l, 1941 UNITED STATE 2.261.348 MANUFACTURE OF RECTIFIER, ELEMENTS Roger Doucot,

Livry-Gargan,

Seine-et-Oise,

France, assignor, by mesne assignments, to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania No Drawing. Application November 2, 1938,

In France April 20, 1938 Serial No. 238,493.

7 Claims.

The present invention relates to the manufacture of elements showing the phenomenon of asymmetric conductivity (rectifiers), for example, of the copper oxide type and has for its object to stabilise the resistance in the blocking direction and at the same time to enable the element's being exposed without deterioration to service voltages exceeding those which can be applied to such elements according to the present state of the art.

According to the invention to the copper a metal or number of metals belonging to the eighth group of the periodical classification of the elements is or are added, for example, iron, nickel, or cobalt, by direct incorporation resulting in a mixture, an alloy or even a compound, or furthermore, by being deposited on the surface oi the copper, which may for example be carried out electrolytically.

The incorporation of the foreign metal or metals can further be effected by hot decomposition of a salt, for example nitrate, which when heated yields an oxide which is thus incorporated fcr example in the copper oxide When testing rectifier elements made accord- A ing to the invention it is found that the curve of the current in the blocking direction obtained by a predetermined constant voltage as a function of the time, that is to say the curve of the intensities passing from the copper to the oxide, shows a much more flattened attitude and clearly lower ordinates than the curve for elements produced by the customary process. ,It is furthermore found that increased percentages of the metal or metals of the eighth group bring about a further reduction or" the value of the ordinates of this curve.

Tests under voltage have shown that the backwards current increases much less with an increase of voltage than in rectifier elements obtained according to prior processes. As a consequence the service voltage may be substantially increased, which allows to reduce correspondingly the number of elements for a given use.

It will be evident that the indications'given hereinabove are only given by way of example for illustrating the invention and are by no means limitative. The same is true in respect oi the metals mentioned which are only the most used metals out of the eighth group.

Although I have herein shown and described only one process for the manufacture of electrical rectifiers embodying my invention, it is,

understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having claim is:

1. The process for stabilizing the reverse resistance and increasing the service voltage of a copper oxide rectifier element which consists in incorporating into the copper oxide of the element one or more of the metals. of theeighthperiodic group, said incorporation being effected by hot decomposition of a salt which when heated yields an oxide. 2. The process for stabilizing 'the reverse resistance and increasing the service voltage 01' a 1 copper oxide rectifier element which consists in incorporating into the copper oxide of the element one or more of the metals of the eighth periodic group, said incorporation being eiiected by hot decomposition of a nitrate.

3. The process for stabilizing the reverse resistance and increasing the service voltage oi. a copper oxide rectifier element which consists in incorporating "into the copper oxide of the element one or more of the metals of the eighth periodic group, said incorporation being effected by hot decomposition of a nitrate which'when heated yields an oxide.

4. The process for stabilizing the reverse resistance and increasing the service voltage of a copper oxide rectifier element which consists in electrolytically depositing on the surface of the copper from which the element is formed a metal or a number of metals belonging to the eighth periodic group.

5. The process for stabilizing the reverse resistance and increasing the service voltage 0! a copper oxide rectifier element which consists in electrolytically depositing on the surface of the copper from which the element is formed one or more of the metals iron, nickel, or cobalt.

6. A copper oxide rectifier element having deposited'on the copper from which the element is formed one or more of the metals of the eighth periodic group.

7, A copper oxide rectifier element having I electrolytically deposited on the copper from which the element is formed one or more of the metals iron, nickel, or cobalt.

ROGER nouco'r.

thus described my invention, what I 

